This invention relates to the field of aircraft cockpit windshield and canopy apparatus of the crew protection affording variety.
The characteristics needed in a military aircraft windshield system are found to depend upon the mission performed by the aircraft. In the design of a present-day military aircraft the windshield system is, in fact, another of the systems which should be specialized in order to optimize the aircraft to its mission. The relatively large and slow speed windshield system of a transport aircraft, the smaller, higher speed windshield system on some fighter aircraft, and large one piece transparencies that combine the windshield and canopy on one fighter aircraft are ready present-day examples of different and specific designs in the windshield art.
In the present state of the aircraft design and materials technologies, moreover, a windshield arrangement suitable for a modern variety of aircraft uses is not technically feasible--in view of the large number of compromises such a design necessarily entails. It is possible, however, with presently available materials to accomplish a windshield system in which the number of design compromises required is greatly limited through the use of selectable and movable windshield panels. In such a system, each selectable panel provides characteristics that are capable of meeting specific threat conditions to be encountered by the aircraft. The present invention is an example of this selection of windshield characteristics to meet anticipated specific threats concept.
The prior patent art includes several examples of aircraft windshield systems that are arranged to meet specific aircraft needs. Included in these prior art windshield arrangements is the two-piece structure of W. E. Fellers et al, disclosed in U.S. Pat. No. 3,361,881, wherein the innermost windshield member also functions as a combining glass for a heads-up display apparatus. Also included is the movable member windshield system of A. G. Kinnerley et al, disclosed in U.S. Pat. No. 3,331,570, in which the aircraft pilot is provided with a limited degree of forward vision during high-speed flight through the use of a movable shielding means; and the cabin enclosure apparatus of W. A. Spivak et al, disclosed in U.S. Pat. No. 3,334,846, in which a dual windshield having inner and outer components is described. Also included in this prior patent art is the theft protecting windshield apparatus of J. T. Webb, disclosed in U.S. Pat. No. 4,299,361; the window panel and sealing arrangement of C. W. G. Hall, disclosed in U.S. Pat. No. 4,645,146; the deflector system of F. E. Jarecki, disclosed in U.S. Pat. No. 3,215,377; and the blast shielding apparatus of F. C. Guill disclosed in U.S. Pat. No. 4,650,137. These prior art windshield systems have not, however, provided a degree of flexibility and the range of characteristics available from the windshield system of the present invention.